The request would be based on about 4,000 documents the FBI turned over to McVeigh's attorneys earlier this month, just days before he had been scheduled to be executed for carrying out the 1995 blast that killed 168 people and injured hundreds more.

At his office in Tulsa, Okla., Rob Nigh said he plans to meet with McVeigh today at the federal penitentiary in Terre Haute, Ind., and will seek his approval on a request to block the execution.

Nigh declined to comment on the contents of the group of documents he would show McVeigh.

"If he gives us permission to file something, we'll probably file something tomorrow (today)," he said Wednesday. "We're in the process of drafting the paperwork."

McVeigh told a federal judge in December that he would not appeal his death sentence.

In early May, the FBI gave McVeigh's attorneys thousands of documents that it said had accidentally not been turned over to the defense. Attorney General John Ashcroft then postponed McVeigh's execution from May 16 to June 11.

In a statement Wednesday, Ashcroft reiterated that the government would fight any further delay, saying that failure to carry out the sentence "would deny justice for the victims of this crime and for the American people."

Meanwhile, a former FBI agent who worked on the case reportedly told a Republican member of the Senate Judiciary Committee last year that the FBI ignored evidence that might have helped the defense.

Ricardo Ojeda, a former special agent in Oklahoma City, wrote Sen. Charles Grassley, R-Iowa, in March 2000, complaining of corruption and discrimination in the FBI's field office, according to CBS' "60 Minutes II."

"I am also aware of instances in other cases, including the Oklahoma City bombing, where exculpatory evidence was ignored and not documented. Including exculpatory information I personally gathered from leads assigned me in the case," Ojeda wrote.

The FBI said Ojeda's records were turned over to McVeigh's lawyers, but that none of his investigation was used at trial. Ojeda said he was fired from the FBI after testifying in a discrimination hearing against FBI management.